Can chronotype and social jet lag predict burnout among physical therapists?

Figures & data

Table 1. Comparison of the studied variables between men and women in the studied group of physical therapists

		Men (N = 16)		Women (N = 38)
		M	SD	M	SD	F	p
Age		34.81	11.41	39.39	12.10	1.669	0.202
Practice time (years)		11.81	12.01	16.62	12.71	1.662	0.203
Packyears of smoking		2.50	7.75	1.67	6.88	0.151	0.699
SJL (hours)		0.86	0.91	0.67	0.62	0.791	0.378
CQ	ME	18.06	5.04	19.18	4.87	0.585	0.448
	DI	19.75	4.28	19.39	4.20	0.080	0.779
PSQI total score		4.38	2.06	5.55	3.13	1.910	0.173
LBQ	Psychophysical Exhaustion	17.69	6.77	16.68	5.16	0.352	0.555
	Relationship Deterioration	18.50	4.72	14.87	5.00	6.127	0.017
	Sense of Professional Ineffectiveness	13.00	5.05	13.63	3.80	0.202	0.657
	Disillusionment	14.94	7.33	13.18	5.51	0.932	0.339

SJL – social jetlag, CQ – Chronotype Questionnaire, ME – Morningness-Eveningness, DI – Distinctness of the Rhythm, PSQI – Pittsburgh Sleep Quality Index, LBQ – Link Burnout Questionnaire, M – mean, SD – standard deviation, F – F statistics (analysis of variance), p – probability in the statistical test.

Table 2. Pearson correlation quotients between the studied variables in the analysed group of physical therapists

			Age	1	2	3	4	5	6	7	8	9
1	Practice time (years)		0.988**
2	Packyears of smoking		0.325*	0.336*
3	SJL (hours)		−0.284	−0.292	−0.217
4	CQ	ME	−0.187	−0.188	−0.330*	0.270
5		DI	−0.061	−0.067	0.001	−0.087	0.263
6	PSQI total score		0.130	0.103	−0.186	0.058	0.137	0.099
7	LBQ	Psychophysical Exhaustion	0.163	0.152	0.121	−0.179	−0.021	0.372*	0.221
8		Relationship Deterioration	−0.130	−0.146	0.177	0.114	−0.082	0.311	0.097	0.545**
9		Sense of Professional Ineffectiveness	0.045	0.065	−0.031	−0.345*	−0.011	0.010	0.129	0.324	0.174
10		Disillusionment	0.072	0.039	0.117	−0.184	0.115	0.378*	0.269	0.593**	0.512**	0.319

SJL – social jetlag, CQ – Chronotype Questionnaire, ME – Morningness-Eveningness, DI – Distinctness of the Rhythm, PSQI – Pittsburgh Sleep Quality Index. LBQ – Link Burnout Questionnaire, * – p < 0.05, ** – p < 0.01 (concerns p-values after Benjamini–Hochberg correction)

Table 3. Parameters (B) identified for the prediction of Link Burnout Questionnaire (LBQ) dimensions in the studied sample of physical therapists; effect sizes are given as semi-partial correlations (sR) of linear regression models

	B	B 95% CI		sR	t	p
Psychophysical exhaustion
R^2 = 0.312; F = 5.012, df = 6, p < 0.001
Intercept	22.030	12.420	31.641		4.612	<0.001
ME	−0.577	−0.965	−0.190	−0.342	−2.999	0.004
AM	0.348	0.013	0.684	0.238	2.087	0.042
SJL	−12.345	−19.885	−4.804	−0.375	−3.294	0.002
Subjective sleep quality 1 vs 0	0.847	−1.294	2.988	0.091	0.796	0.430
Subjective sleep quality 2 vs 0	3.116	−0.189	6.422	0.216	1.897	0.064
SJL*ME	0.576	0.202	0.951	0.353	3.098	0.003
Sense of professional ineffectiveness
R^2 = 0.102; F = 7.018, df = 1, p = 0.011
Intercept	14.911	13.363	16.460		19.320	<0.001
SJL	−2.007	−3.528	−0.487	−0.345	−2.649	0.011
Relationship deterioration
R^2 = 0.370; F = 7.250, df = 5, p < 0.001
Intercept	18.068	15.601	20.535		14.725	<0.001
Alcohol 1 vs 0 pt	−2.897	−5.641	−0.152	−0.231	−2.122	0.039
Alcohol 2 vs 0 pt	0.385	−2.370	3.140	0.031	0.281	0.780
Alcohol 3 vs 0 pt	6.257	2.253	10.261	0.342	3.142	0.003
Energy drinks 1 vs 0 pt	−5.317	−8.852	−1.782	−0.330	−3.025	0.004
Energy drinks 2 vs 0 pt	4.611	0.018	9.203	0.220	2.019	0.049
Disillusionment
R^2 = 0.232; F = 6.330, df = 3, p = 0.001
Intercept	5.432	−1.766	12.630		1.516	0.136
AM	0.513	0.155	0.871	0.347	2.880	0.006
Sleep disturbances 1 vs 0 pts	−2.705	−5.203	−0.207	−0.262	−2.175	0.034
Sleep disturbances 2 vs 0 pts	3.864	0.535	7.194	0.281	2.331	0.024

R² – coefficient of determination; F – F statistics (linear regression); df – degrees of freedom; p – probability in the statistical test, t – statistics in the test, ME – Morningness-Eveningness score, DI – Distinctness of the Rhythm score, SJL – social jetlag, Subjective sleep quality – scoring in the Pittsburgh Sleep Quality Index (PSQI) component 9:0 – very good, 1 – fairly good, 2 – fairly bad; Alcohol scoring: 0 – less than or equal to 1 unit per week, 1–2 to 5 units per week, 2–6 to 10 units per week, 3 – 11-20 units per week; Energy drinks: 0 – does not drink at all, 1 – less than 1 per day, 2 – one per day; Sleep disturbances = scoring in the PSQI component 5 tapping into causes of sleep interruptions.

Figure 1. The association between psychophysical exhaustion and social jetlag (SJL): actual and modelled data based on individual chronotype questionnaire morningness-eveningness (ME) score in the studied group of physical therapists. LBQ – link burnout questionnaire